Doctors are worried that those who overuse ERs -- dubbed "superusers" -- are causing a severe burden on U.S. emergency departments.
"When things are crowded, people are rushed, they can feel the stress of extra patients waiting to be seen, and they tend to make more mistakes," Dr. Jeff Dubin an emergency physician at MedStar Washington Hospital Center, and author of a new study on superusers, told CBS News.
Superusers are a small but expensive group: One large study conducted from 2009-2012 at a Los Angeles hospital noted that 99 percent of ER visitors come in fewer than 10 times a year, with nearly 67 percent coming in just once. But, the remaining 1 percent of visitors accounted for thousands of visits in one year.
According to the Journal of the American Medical Association, ER visits have been on the rise for decades, even as the number of emergency departments has been slowly decreasing across the country. .
Dubin says one of the problems is "boarding." When the ER runs out of beds, patients are still admitted after two hours of waiting. Once admitted, they have to be monitored, and patients can wait six to eight hours, even 24 hours in some cases. As patients pile up, physicians have to start examinations in the hallways, and it gets harder to discharge patients quickly.
"It's like a party where people keep coming in, and no one's leaving," said Dubin.
While superusers don't add an immediate burden, they add up over time in repeat visits.
"Anything that adds to crowding makes doctors more vulnerable to error," he said.
Some doctors consider a "frequent user" to be someone with over 20 visits to the ER a year, while others study the number of 9-1-1 calls. Some visitors, while others have serious chronic conditions like liver and heart disease that require repeated medical attention.
Stephen Dorner, a medical student at Vanderbilt University, conducted a separate study to build a better profile of superusers. He noticed that some patients weren't coming in as often as some "frequent fliers," but were being admitted repeatedly for chronic conditions, sometimes at the referral of their primary care physician.
In the ER, primary care doctors can rely on their patients being admitted and can then see them alongside a specialist if needed.
"There are patients who have serious medical conditions who see the ER as the point of access," Dorner said.
ER doctors are experimenting with ways of preventing heavy crowds, focusing on superusers. In California, San Francisco General Hospital teamed up with the fire department to give specialized attention to frequent 9-1-1 callers.
"Sometimes we have patients present to the ER who don't have a medical emergency," said Dr. Julian Villar, who assisted the program in San Francisco and reported his findings in a new study. According to Villar, many patients are using the ER to access other services, such as substance abuse treatment.
He says although his program had success, it came to a stop once the research finished. Villar said the problem was an issue of resources, including money and personnel.
The studies were presented Oct. 14 and 15 at the American College of Emergency Physicians (ACEP) annual meeting in Seattle. They are considered preliminary since they have yet to be published in a peer-reviewed journal.